Bobcat 773F series power issues/fuel issues

[james c]

I'm new to this forum but have a 1999 773 when its cold out side it runs fine as it gets to normal running temp it will start to loose power whether under load or just sitting, I can use the primer bulb to make the RPMs come up to normal and it will run fine while doing this. So I've replaced all the fuel lines installed a new pickup pump, and tried running the machine off of a qt. bottle just in from of the primer bulb in case it had a vac. leak on the inlet side of the fuel system,I've changed the primer bulb just to be safe also. I l have also changed the fuel filter installed an inline filter along with the main fuel filter when it dies it will start back up but just has a rough idle due to lack of fuel, once the machine cools off it runs fine again until it warms up again. I'm not sure what to do now, I'm just not sure that the injector pump could go from working fine to not just by warming the engine up. Does anyone have any suggestions thanks James C

 

[Bswwood]

Next step would be to replace the lift pump which supplies fuel to the injection pump. Google part number 6655216 and you will see what you need, very easy to change and reasonably priced from aftermarket part suppliers.

 

[mmsllc]

Next step would be to replace the lift pump which supplies fuel to the injection pump. Google part number 6655216 and you will see what you need, very easy to change and reasonably priced from aftermarket part suppliers.

If it were my machine, I would install an electrical diesel fuel pump & bypass the mechanical fuel pump. I would do this to see if the condition goes away. If the condition goes away, I would look harder at your mechanical lift pump & how it is driven off the injection pump. This might be the cheapest approach to this issue. I might would replace the fuel pick up tube in the fuel tank, too. They typically run about $10 to $15 from the dealer. Those things are a VERY common problem. Let us know what else you can so we can better help you out.

 

[james c]

Next step would be to replace the lift pump which supplies fuel to the injection pump. Google part number 6655216 and you will see what you need, very easy to change and reasonably priced from aftermarket part suppliers.

I have replaced the lift pump and it didn't help my new thing to try is the shut off solenoid, someone suggested it could be getting weak and my not be holding the shut off valve all the way open thus starving the machine after the coil heats up

 

[james c]

I have replaced the lift pump and it didn't help my new thing to try is the shut off solenoid, someone suggested it could be getting weak and my not be holding the shut off valve all the way open thus starving the machine after the coil heats up

i've tried a bottle to rule of fuel issues in front of the primer bulb and I've changed the lift pump so tonight i'm testing the solenoid shut off for the fuel incase its getting weak and closing a little and starving the unit when it heats up. thanks for all your support